Most current bioanalytical assays are inaccessible to developing economies. Current diagnostic assays typically require large and expensive laboratory instruments that are operated by trained personnel. Although “dipstick” technologies have increased the accessibility of many assays, many of the assays are too expensive for low-cost settings and often require relatively large sample volumes. Thus, there remains a need for low-cost diagnostic assays that are not cumbersome and that can be performed on small sample volumes.